1. Field
Embodiments of the present invention relate to a washing method of a washing machine using natural soap-based detergent.
2. Description of the Related Art
Generally, a washing machine (conventionally, a drum washing machine) includes a wash tub to receive fresh water (wash water or rinse water) therein, a cylindrical drum rotatably installed in the wash tub to receive laundry therein, and a motor to rotate the drum. When the drum is rotated, the laundry received in the drum is washed via tumbling motions along an inner wall of the drum.
The washing machine washes laundry via a series of operations including a washing operation to separate contaminants from laundry using detergent-dissolved water (i.e., wash water), a rinsing operation to remove bubbles or residual detergent from the laundry using water not containing detergent (i.e., rinse water), and a dehydrating or “spin” operation to dehydrate the laundry at a high speed.
In the washing operation, after detergent is put in the wash tub along with water (i.e., wash water), the drum is rotated clockwise or counterclockwise based on operation of the motor to generate streams of the detergent-dissolved water (i.e. a mixture of water and detergent) to penetrate the laundry, thereby enabling removal of contaminants from the laundry. Since only synthetic detergent has been used with conventional washing machines, a control algorithm, i.e., a washing and rinsing algorithm is set based on synthetic detergent.
However, as environmental pollution has intensified in recent years, eco-friendly materials are increasingly utilized as a washing machine detergent. In particular, use of soap-based detergent not containing synthetic materials is increasing. Such soap-based detergent contains natural materials and may be suitable to wash clothes of users who suffer from dermatitis (atopic dermatitis patients or senile pigmentosum) as well as infants and children.
These natural soap-based detergents, however, have difficulty being dissolved in cold water and may undergo gelation when the temperature of rinse water used for a rinsing operation is lower than the temperature of wash water used for a washing operation, thereby leaving behind residue on clothes to be washed, resulting in deterioration in washing quality.